Dragon Ball Z (1989 - 1996)

The story begins 5 years after the Dragon Ball series. Goku now has a son named gohan and has pretty much given up on fighting. Raditz, Goku's brother has traveled to Earth to find out why Goku has not yet destroyed the planet as he was supposed to do. But while as a baby, Goku fell (down a huge cliff) and forgot his real mission. He is an alien known as a sayain. They look just like a human, but have tremendous powers and a monkey like tail which allows them to turn into a giant ape like creature when there is a full moon. Gohan has a tail since he is half sayain and so raditz decides to use him against his brother. Goku is badly beten by raditz and he kidnaps gohan. Piccolo decides to team up with goku to stop this greater evil. After a great battle Gohan reveals his hidden powers against Raditz and nearly kills Raditz. In the end goku sacrifices himself to save earth by letting piccolo hit him with his new move the special beam cannon while he held radditz. Before he dies, Raditz tells them that two evil-saiyans even more powerful then he is, are on route to Earth.
The remaining fighters, Krillin, Yamcha, Tien, and Chaotzu begin their training to battle the evil saiyans, while Piccolo takes off with Gohan to train him in using his new found power. Meanwhile, Goku has to make his way back on Snake Way to King Kai's planet where he trains himself in the secret art of Kaiô-Ken. After the battle the only survivors are Goku, Krillin, and Gohan. So the remaining heroes travel to Piccolo's home planet of Namek to find new dragon balls to wish everyone back to life. After Goku undergoes excrutiating training at 100x Earth's gravity, and witnesses the death of his best friend krillin at the hands of the evil freeza he transforms into a super sayain which gives him about 10x more power than normal, blond hair, green eyes, and a golden aura. With his new powers he kills freeza before the planet is destroyed.
Then after everyone is returned to life and back home on earth the heroes are visited by Trunks the future son of vegeta and bulma. He tells goku that in 3 years 2 evil androids created by the evil scientist Dr. Gero will come and kill everyone. So goku and the others train to be prepared, but this is only the lesser of the troubles. Cell the ultimate creation of gero follows trunks to the pesent time. He is a bio-android created from the combined DNA of all of the heroes,and villains of Dragon Ball. His ultimate goal is to achive "Perfect"status by absorbing Androids 17 & 18. He does so after many battles and finally in the end after Goku has fallen Gohan with his new Super Saiyan 2 powers destroys cell with a massive blast of energy.
Then, 7 years after the battle Goku returns for one day on earth so he can compete in the tenkaichi budokai, and during the battles Majin Buu an evil demon of immense power is reborn and causes the destruction of the etire world. Only with combined forces of good is he defeated and the world restored. The story is later continued in Dragon Ball GT.